A Systematic Study on the Effects of Key Influencing Factors on a Pull-Off Adhesion Test of Organic Coatings

Coatings can protect metallic substrates (e.g., piping, vessels, tubes, etc.) against corrosion attack. The adhesion strength of a coating to its substrate is an essential factor that defines the overall coating integrity and performance. A pull-off adhesion test is commonly performed to determine the coating adhesion strength. This study evaluated the effect of various vital influencing factors on the pull-off adhesion test, including surface preparation of the loading fixture (dolly) and coating surface, types, curing durations and conditions of adhesive, and scoring of coating around the dolly. Test results were systematically analyzed with nonsubjective tools such as ImageJ software for failure mode assessment and statistical analysis (t-test) to compare adhesion values.